Discharge tube containing auxiliary electrodes



DISCHARGE TUBE CONTAINING AUXILIARY ELECTRODES Filed Nay 1925 INVENTOR .JOhA/VA/[J flit/7451. JCHMISQEQ ATTORNEY 5 Patented Mar. 11, 1930 UNITED STATES PATENT OFFICE JoHanNEs MICHAEL scrmimn'sn, or enoss LiICI-ITERFELDE, NEAR BERLIN, GERMANY,

ASSIGNOR TO RADIO PATENTS CORPORATION, on NEW YORK, N. Y., A CORPORA- 'IION OF NEW YORK DISCHARGE TUBE CONTAINING AUXILIARY ELECTRODES Application filed May 6, 1925, Serial No. 28,515, and in Germany January 23, 1924.

An application for this invention has been filed in Germany, January 23, 1924.

This invention relates to ionic emission devices; and particularly glow discharge devices employed in the art of communication trodes, the operation depends on a continuby radio.

An object of the invention is to provide a vacuum tube or bulb containing electrodes, some of which are capable of emitting electrons, and which are so arranged that weak alternating electric currents supplied to the tube can be materially amplified. In practice the desired end is preferably attained with the help of one or more auxiliary electrodes in the tube.

Uther objects and the nature and advantages of the invention will appear from the following description, and the novel features of the invention are defined in the appended claims. But the disclosure is explanatory only, and the right is reserved to make any changes that do not depart from the principle of the invention.

Figure 1 shows diagrammatically the voltage distribution of my preferred vacuum tube, such as an evacuated glass bulb, with, say, four electrodes therein, e. g., a cathode, an anode, and one or more auxiliary electrodes in addition; Fig. 2 shows diagrammatically the tube with the electrodes arranged in the relation shown in Fig. 1.

The fact that the ions are projected from the surface of the cathode by high electric potential and not by heat should be kept in mind, since this invention relates to glow discharge tubes tus.

With prior devices for amplifying weak and not thermionic apparaalternatin currents, consisting of glow discharge .tu es with several auxiliary elec ous discharge between the cathode and one of the adjacent auxiliary electrodes, and upon the fact that, by a second auxiliary electrode, which is disposed in a space free of electronic collisions, the electrons slowly moving from the first auxiliary electrode, are either obstructed or accelerated on their way to the anode. The slowness of their moving is due to the moderate potential of the auxiliary electrode. According to the present invention, the discharge from an electrode to the anode takes place by means of collisions and the counter-moving ions in the space between the two auxiliary electrodes, are excited to stronger or weaker collisions by the creation of an electric field in such space, and thus the conductivity of the discharge path to the anode is increased or diminished. I

That the proportionate influence of the anode stream may be most favorable, it is advisable to weaken the full discharge toward the anode.v This effect can be obtained by a division of the discharge stream; and preferably by disposing a second auxiliary electrode in the tube and bringing it to such moderate potential that a part of the electronic stream goes to the anode and another part goes to the auxiliary electrode. value of this potential is selected for the most elficient operation. Hence one either can mount in the tube three auxiliary electrodes, of which one as described can serve to take part of the discharge, while the other two provide regulation; or use an arrangement with two auxiliary electrodes, one to serve simultaneously to take the discharge and for regulation; while the other is utilized for regulation alone.

It is not necessary to have the regulating electrodes between the cathode and anode.

The regulating electrode may just as well be placed behind as before the anode.

For better explanation of the operation, the distribution of potential in the tube is indicated in the drawing. At the cathode is the full tension of the cathode drop, and

The

weakens the ionization and therewith the conductivity of the discharge path. This operation is altogether different from that of prior glow discharge tubes, and has the advantage that a continuous electron stream is strengt ened or weakened, while with earlier devlces the operation depends on the opening or closing of an electric valve, and thus only the half of the electric oscillation is utilized. Referring to Figure 2 in which the tube with the electrodes are shown, it will be noted that these electrodes are positioned in the same relative position as shown in Figure 1. Connected between the cathode C and plate A'is a potentiometer P which supplies the necessary voltages. At a point D in the potentiometer P, Volta e is applied to the auxiliary electrode AE w ich, it will be noted, has thus applied to it substantially the same voltage otential applied to the 1{late A. The regu ating or control grid R is interposed between the auxiliary electrode AE and plate A and varies the voltages distribution between these two in accordance with input voltage from the input circuit connected at I. The output circuit is connected to the terminal O in the well known manner.

The strength of the stream leaving the cathode is not necessarily varied butmore or less of this stream gets through to the anode as the intervening gas is ionized more orless by means of the auxiliary electrode.

Having described my invention what ..I believe to be new, and desire to secure and rotect by Letters Patent of the United tates is 2- 3 1. In a gas discharge tube, a cathode, anode and electrode, means for applyin a predetermined voltage across said cat ode and anode, means whereby substantially all of said voltage is impressed across said cathode and electrode and substantially onl the anode drop occurs between the electro e and anode.

2. In a gas discharge tube comprising a cathode, an anode and an electrode, the voltage between the anode and electrode comrising normally substantially only the anode rop and means for varying said voltage in accordance with received signals.

3. In a gas discharge tube comprising a cathode, electrode and anode, means to secure a voltage distribution between said elements such that substantially all the voltage drop but the anode drop occurs between the electrode and cathode and only the anode drop occurs between the electrode and anode, and means for varyin the volta e between the electrode and ano e in accor ance with received signals.

4. In a gas discharge tube com rising a cathode, electrode and anode, the v0 tage istribution between said elements being such that substantially all the volta the anode drop occurs between 0 electrode and cathode and only the anode dro occurs between the electrode and anode, an means for varying the voltage between the electrode anii anode in accordance with received signa s.

5. In a gas discharge tube, comprising a cathode'emitting a discharge, an anode and an electrode, a further electrode for dividin the discharge emanating from said cat ode, the voltage difierence between said further electrode and anode being approximately equal to the anode drop of said second electrode and means to control the discharge to said second electrode.

6. In a gas discharge tube, comprising a cathode, an anode, a gaseous discharge therebetween, a further electrode for dividing the discharge stream emanating from said cathode, the voltage applied to said anode difi'ering from that applied to said further electrode by an amount approximately equal to the voltage drop at said second electrode and a control electrode arranged to act on a discharge between said electrodes. I

7. In a gas discharge tube, containing a cathode, an anode and electrode arranged between said cathode and anode, said electrode bein connected to a positive otential smal er than the potential applie to said anode by an amount approximately equal to the voltage drop occurring at said anode and a control electrode placed between said auxiliary electrode and said anode.

8. In a gas discharge electrode, a cathode electrode, an anode electrode, a gaseous discharge therebetween, means for applying a voltage across said first and second electrodes, the voltage gradient of said applied voltage being such that over a predetermined portion of the tube, there is substantially no voltage chan e and the voltage is substantially equal to t e voltage drop at said anode electrode and means or applyin an input voltage across said predetermine portion.

9. In a gas discharge tube, comprising a cathode and an anode, a gaseous discharge therebetween, an electrode interposed between said cathode and said anode the voltage gradient of said tube being, such that substantially all of the drop occurs between the cathode and the electrode and a rid for varying the voltage between said e ectrode and said anode in accordance with received signals.

fSi ed at Berlin, Germany, this 27th day 0 arch, A. D. 1925. JOHANNES MIC EL SCHMIERER.

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